The present application relates generally to controllers, architectures, methods and systems for enabling vehicles to drive in a partially or fully autonomous mode and/or closely follow one another safely using automatic or partially automatic control.
In recent years significant strides have been made in the field of automated vehicle control. One segment of vehicle automation relates to connected vehicle control such as vehicular convoying systems that enable vehicles to follow closely together in a safe, efficient and convenient manner. Following closely behind another vehicle has the potential for significant fuel savings benefits, but is generally unsafe when done manually by the driver. One type of vehicle convoying system is sometimes referred to as vehicle platooning in which a second, and potentially additional, vehicle(s) is/are automatically or semi-automatically controlled to closely follow a lead vehicle in a safe manner.
The fuel efficiency advantages of platooning are particularly noticeable in fields such as the trucking industry in which long distances tend to be traveled at highway speeds. One of the on-going challenges of vehicle platooning and convoying systems is creating controller systems architectures that are cost effective, efficient and meet the stringent safety standards required for integration into mainstream road vehicles. Although existing gap control system architectures work well, there are continuing efforts to develop improved platoon controllers that provide safe and fuel efficient operation while delivering a comfortable user experience.
Beyond platooning there are a wide variety of partially or fully autonomous vehicle control application in which verified knowledge about what a second vehicle is doing can be very helpful in managing the partially or fully autonomous control of a host vehicle.
There are several industry and government standards relating to road vehicle safety. One well known international standard for classifying the functional safety of electrical and electronic system in road vehicles is the ASIL (Automotive Safety Integrity Level) standard defined by ISO 26262—Functional Safety for Road Vehicles standard. There are four safety integrity levels identified by the ASIL standard (ASIL-A, ASIL-B, ASIL-C and ASIL-D) with ASIL-A corresponding to the lowest level compliance requirements and ASIL-D representing the highest integrity requirements. Items having safety requirements that are not dictated by the standard are designed as QM (Quality Management).
Many ECUs, powertrain control modules (PCMs) and other controllers used in commercially available road vehicles are designed to expect that all commands that they receive come from ASIL compliant components that conform to a particular minimum ASIL level. Therefore, in some circumstances, it is desirable for control commands issued from the platoon controller to be ASIL rated or to meet other designated reliability criteria or standard. At the same time, some of the data (such as GPS position data) that is useful in platoon control does not itself have a reliability that can is suitable for ASIL rating. The present application describes platoon control system architectures that are particularly well suited for efficiently handling platooning control related tasks using information available from a variety of sources. When desired, the powertrain control commands ultimately issued by the control system may be ASIL rated.